The present invention relates to a device for protecting a pedestrian.
Providing an airbag for motorcyclists and bicyclists is discussed in German Published Utility Model Specification No. 298 071 71, in which a gas generator is affixed to a motorcycle or bicycle, respectively.
An exemplary device according to the present invention for protecting a pedestrian is believed to have an advantage in that an airbag device may also be available for a pedestrian. This is believed to be advantageous for people over approximately 50 years of age, since these people may have a high probability, in the event of a fall, of suffering a bone fracture, such as, for example, a femoral, femoral neck, pelvic, coccygeal, lumbar or other fracture of the locomotor apparatus. This may be avoided or at least reduced in severity by an exemplary device according to the present invention. This may result in greater safety for elderly and those at-risk and therefore in lower burdens on the health system. An exemplary device according to the present invention may also be used by mountain climbers and hikers and may thus also significantly reduce the severity of injuries, in the event of possible accidents, or may even prevent injuries. A cold gas generator is provided in an exemplary device according to the present invention, since the discharge gas temperature of a cold gas generator approximately corresponds to the ambient air temperature. The cold gas generator may comprise, for example, a steel bottle as a pressure container that is partially filled with noble gases argon or helium at high pressure, up to 600 bar, and is then pyrotechnically opened by piercing a sealing membrane or by moving a sealing screen laterally.
It is believed to be advantageous that an exemplary device according to the present invention is provided as a belt, so that it may, for example, be worn around the hips, with a width of, for example, approximately 10 cm and a thickness of 3 cm. Such a belt may then, through a triggered airbag, cushion its wearer against stresses occurring on the hips, buttocks, spinal column, and other bones, in the event of a fall, so that bone fractures may be avoided. The airbag may also protect against tissue injuries caused by falls on pointed or edged objects.
In addition, it is believed to be advantageous that an exemplary device according to the present invention includes a charging circuit and an energy store, so that the device may, for example, be worn by its wearer for an entire day and then be recharged by connecting the device to an available electricity network in the evening. The energy store may include a rechargeable store having high power density, such as, for example, double layer capacitors according to the Maxwell principle. Such energy stores may be recharged within 15 seconds, by being reconnected to the network. The electronics may be implemented, so that they are supplied for approximately 15 hours, without interruption.
Furthermore, it is believed to be advantageous that a substantial part of the electronic components of an exemplary device according to the present invention may be located on a flexible printed-circuit board, which may be easily integrated in the belt, so that the exemplary device may be worn comfortably by a person.
Furthermore, it is believed to be advantageous that the impact sensor includes an acceleration sensor allowing measurements of acceleration, both in the horizontal direction, which may occur during travel in a motor vehicle or an aircraft, and in the vertical direction, which may occur, for example, during a fall. Through a suitable triggering algorithm in a processor, only triggering events that unequivocally indicate a fall are recognized. These may include high accelerations in the vertical direction. A triggering algorithm including, for example, an adaptive threshold, may be provided for this purpose, with extensive tests for parameter determination. Integrated acceleration signals may be evaluated, i.e., speed signals.
The use of a flexible printed-circuit board is believed to be advantageous for use by a pedestrian, since an exemplary device according to the present invention may be integrated in a belt, which may be comfortable to wear.